[U-Boot] [PATCH] lib_ppc: rework the flush_cache

Dave Liu
2008-12-02T03:47:57Z

- It is possible to miss flush/invalidate the last
cache line, we fix it at here.
- add the volatile and memory clobber.

the bugs is pointed by Scott Wood.

Signed-off-by: Dave Liu <daveliu@freescale.com>
---
lib_ppc/cache.c | 36 +++++++++++++++++-------------------
1 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/lib_ppc/cache.c b/lib_ppc/cache.c
index 72c838e..dd4eb22 100644
--- a/lib_ppc/cache.c
+++ b/lib_ppc/cache.c
@@ -25,29 +25,27 @@
#include <asm/cache.h>
#include <watchdog.h>

-void flush_cache (ulong start_addr, ulong size)
+void flush_cache(ulong start_addr, ulong size)
{
#ifndef CONFIG_5xx
- ulong addr, end_addr = start_addr + size;
+ ulong addr, start, end;

- if (CONFIG_SYS_CACHELINE_SIZE) {
- addr = start_addr & (CONFIG_SYS_CACHELINE_SIZE - 1);
- for (addr = start_addr;
- addr < end_addr;
- addr += CONFIG_SYS_CACHELINE_SIZE) {
- asm ("dcbst 0,%0": :"r" (addr));
- WATCHDOG_RESET();
- }
- asm ("sync"); /* Wait for all dcbst to complete on bus */
+ start = start_addr & ~(CONFIG_SYS_CACHELINE_SIZE - 1);
+ end = (start_addr + size) & ~(CONFIG_SYS_CACHELINE_SIZE - 1);

- for (addr = start_addr;
- addr < end_addr;
- addr += CONFIG_SYS_CACHELINE_SIZE) {
- asm ("icbi 0,%0": :"r" (addr));
- WATCHDOG_RESET();
- }
+ for (addr = start; addr <= end; addr += CONFIG_SYS_CACHELINE_SIZE) {
+ asm volatile("dcbst 0,%0" : : "r" (addr) : "memory");
+ WATCHDOG_RESET();
}
- asm ("sync"); /* Always flush prefetch queue in any case */
- asm ("isync");
+ /* wait for all dcbst to complete on bus */
+ asm volatile("sync" : : : "memory");
+
+ for (addr = start; addr <= end; addr += CONFIG_SYS_CACHELINE_SIZE) {
+ asm volatile("icbi 0,%0" : : "r" (addr) : "memory");
+ WATCHDOG_RESET();
+ }
+ asm volatile("sync" : : : "memory");
+ /* flush prefetch queue */
+ asm volatile("isync" : : : "memory");
#endif
}
--
1.5.4